1. Field of the Invention
The present invention relates to a device and a method for operating a quantity control valve e.g., for supplying fuel to a high-pressure pump, which quantity control valve is provided, for example, with a solenoid valve which is electromagnetically activatable by a coil.
2. Description of Related Art
A method is known from published German patent application document DE 10 2007 035 316 for controlling a quantity control valve having a solenoid valve which is electromagnetically activatable by a coil, in which the coil of the solenoid valve is energized with a first current value in order to close the solenoid valve for supplying fuel to the high-pressure pump, during closing of the solenoid valve the first current value being lowered to a second current value in such a way that emission of audible sound, generated during closing of the solenoid valve during operation of the internal combustion engine, is at least partially reduced.
A method is known from German patent application DE 10 2008 054 513, not pre-published, for controlling a quantity control valve which is influenced by an electromagnetic actuating device. A control signal supplied to the electromagnetic actuating device is defined by at least two parameters, in an adaptation process at least one first parameter of this control signal, with the second parameter fixed, being successively changed from a starting value to an end value at which, at least indirectly, closing or opening of the quantity control valve is no longer detected or is just detected, after which the first parameter is at least preliminarily fixed based on the end value, and the preliminarily fixed first parameter is adapted on the basis of at least one instantaneous operating variable of the fuel injection system, or the second parameter is adapted on the basis of at least one instantaneous operating variable of the fuel injection system and the preliminarily fixed first parameter.
These adaptation methods known from the related art vary the parameters of the control signal of the quantity control valve in such a way that the closing behavior of the quantity control valve is appropriately selected. A characterization of the behavior of the quantity control valve does not take place.
German patent application DE 10 2008 054 512, not pre-published, proposes that, for controlling a quantity control valve which is activated by an electromagnetic actuating device, at least one parameter of a braking pulse is a function of an efficiency of the electromagnetic actuating device and/or of a supply voltage of a voltage source, and/or of a temperature, in particular of a component of the fuel injection system or of the internal combustion engine. The following procedure is used to characterize the efficiency of the electromagnetic actuating device: In an adaptation process, energy supplied to the electromagnetic actuating device is successively changed from a starting value to an end value at which closing or opening of the quantity control valve is no longer detected, or is just detected. The end value or a variable based thereon is used for characterizing the efficiency of the electromagnetic actuating device.
The particularly accurate adaptation of the control of the quantity control valve to the specimen properties requires an accurate characterization of the specimen properties. Two or more parameters are often necessary for this characterization. However, two parameters are not independently ascertainable from only one measurement, as known in the related art.